Homogeneous photo-Fenton system is widely studied and reported to be a promising method for wastewater treatment [R. G. Zepp, B. C. Faust, J. Hoigné, Environ. Sci. Technol. 26 (1992) 313-319; K. H. Chan, W. Chu, Chemosphere 51(2003) 305-311; (c) Y. Sun, Joseph J. Pignatello, Environ. Sci. Technol. 27 (1993) 304-310.]. The major disadvantage of such a system is, reactions are to be studied at acidic pH <3 and it is difficult to remove the sludge containing Fe ions after the treatment. The latter step is expensive and not economical. In literature photochemical studies on immobilized Fe ions involved different supports.
Fenton reactions need technically simple equipment and it creates sludge and subsequent disposal problems constitutes the mainly limitations of the process. The pollutants due to metallic salts can be in principle avoided. A good alternative to homogeneous photo-Fenton system can be heterogeneous photocatalysis. The efficacy of the system is compared by measuring the phenol degradation at different experimental conditions to evaluate the dependence of the degree of mineralization. Search engines like Lycos [www.lycos.co.uk], Yahoo [yahoo.co.uk] and Googles [google.com] allow most of the systems to identify photo-Fenton supported areas.
Photochemical studies on immobilized Fe ions involved different supports like silica, nafion membranes, carbon fabric, Clay etc. The immobilization of Fe (III) ions on the cationic exchange resins (Amberlite IRA200) as a photocatalyst for degradation of organic pollutants also being reported [J. Feng, X Hu, Po. L. Yue, Environ. Sci. Technol. 38 (2004) 269-275; A. Bozzi, T. Yuranova, E. Mielczarski, J. Mielczarski, P. A. Buffat, P. Lais, J. Kiwi, Appl. Catal. B 42 (2003) 289-303.; T. Yuranova, O. Enea, E. Mielczarski, J. Mielczarski, P. Albers, J. Kiwi, Appl. Catal. B 49 (2004) 39-50; J. Li, W. Ma, Y. Huang, X. Jao, J. Zhao, Y. Xu, Appl. Catal. B 48 (2004) 17-24]. Thus, a support can be chosen for the immobilization of Fe ions that should resist the oxidative attack during Fenton process without loss in catalytic performance. The present investigation was undertaken to provide practical assessment of photocatalytic treatment of immobilized Fe (III) over HY zeolite to have an eco-friendly photo-Fenton catalyst.